1. Technical Field
The present disclosure relates to a light emitting device applicable, for example, to purposes such as an indicator, a lighting luminaire, a display, and a backlight light source for liquid crystal display.
2. Background Art
Light emitting devices using light emitting elements such as light emitting diodes or laser diodes are employed in various fields such as general lighting such as in-door lighting, on-vehicle lighting, and backlight for liquid crystal displays. Requirements for higher performance in those light emitting devices are growing daily, and light emitting diodes of further higher output (higher luminance) and lower cost are demanded. Light emitting diodes in various color tones are required according to recent applications, and moreover, the range of color tone is very narrowly limited. In some cases light emitting diodes are used in combination with lenses of secondary optical system, etc., and light emitting diodes which have compatibility with lenses of secondary optical system are also required.
In order to realize white light emitting diodes, light emitting devices which employ combinations of blue light emitting diodes and yellow fluorescent materials (for example, YAG fluorescent materials) have been in use. This may be obtained by injecting a mixture of a resin and a fluorescent material in a region where alight emitting element is mounted.
After mounting a light emitting element, the resin to seal the light emitting element is generally injected in a recess where the light emitting element is mounted. Such recess is formed by, for example, processing a recess in a lead frame, or defined in a resin package which is integrally molded with a lead frame, etc., typically formed by way of mold processing, so that recesses of a relatively uniform shape and size can be manufactured.
See Patent Literature 1: JP 2011-216875A.
See Patent Literature 2: JP 2012-504341A.
See Patent Literature 3: JP 2011-009298A.
However, a disadvantaged resin package type light emitting device which is integrally molded with the lead frame may include a gap (P—N gap) which occurs between the lead frame components in its light emitting portion, which may result in absorption of light emitted from the light emitting element at the P—N gap.